Searchers are close to entering the collapsed spire of Christchurch Cathedral, where up to 22 people are believed to have been killed during last week's 6.3-magnitude earthquake in Christchurch.

A Urban Search and Rescue (USAR) team was preparing to access the inside of the spire, USAR and the Fire Service said in a statement this afternoon.

"This will then allow the systematic and controlled deconstruction of the debris to ascertain the location and recover of any victims in this area."

The focus search efforts today moved from rescue to recovery, but buildings would still be treated as if there were survivors, said Jim Stuart-Black, the Fire Service's head of the USAR teams.

"It is highly, highly unlikely that we will encounter anybody who is alive, but clearly there is the occasional miracle, so we conduct our operations first of all to allow for that miracle," he told a press conference this afternoon.

USAR teams conducted their operations with care and consideration and when they came across a body "we treat them as one of ours".

Mr Stuart-Black said following today's decision they would consider their planning and resource requirements over the next day or two.

Operations would continue 24/7, he said.

"What we now turn our attention to is to work very carefully with heavy machinery to slowly start clearing debris from all the streets checking as we go."

They would take apart damaged buildings in a controlled and careful manner, Mr Stuart-Black said.

At the Forsyth Barr building, where a 24-hour operation was underway, no stairs were available from the 10th floor to the ground.

In order to continue the search a section of wall needed to be removed to enter the building and remove the collapsed stairwell, which the US team said was a significant job.

New Zealand and British teams expected to complete taking down the concrete floors at the Pyne Gould Corporation building late tomorrow or early Saturday.

Searching at the 26-storey Hotel Grand Chancellor was nearly complete, but parts of the stairwell were blocked by rubble.

Japanese, Chinese and New Zealand teams continued searching at the CTV building, which needed to be done during the day.

Around 100 bodies are thought to be in the building, including more than 60 staff and foreign students from the King's Education English language school.

Civil Defence teams, Fire Service staff and police also continued to visit streets and properties outside the CBD to reassure and support people, and would respond with specialist USAR if required.

Teams from Singapore and Australia were also working as part of the USAR in Christchurch.